The aim of this work is to estimate the number of Seyfert nuclei missing in catalogs due to obscuration by the dust disc in host spiral galaxies. We compared the distribution of inclinations of host galaxies of Sy1s and Sy2s with that of in control sample of spiral galaxies, and found that the relative number of Seyferts is higher in almost faceon galaxies with i < 30° and smaller in highly inclined, i > 61°, spiral galaxies without active nuclei. We conclude that the difference found is due to absorption of the Seyfert nuclei by the dustdisc of inclined galaxies. We estimate that about 100% and 50% of the observed Sy1s and Sy2s respectively are missing.

We are grateful to the referee for a careful reading of the paper and valuable suggestions for its improvement. HMT thanks the IPAC (Pasadena, CA, USA) for hospitality. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.